How should I facebook chat this girl?

[Eric]

Im a 10th grader in high school and there is this girl I've been liking since September. Weve been in the same school for a while but I only started liking her now. So I have now befriended her and now Im just waiting for a school dance or something so we can hook up and than see where things end up. Its not like I want a full relationship with this girl but I have liked her for a while now and I just want something to happen. A couple days ago a new girl came to our school and I share alot of classes with her so I have wanted to introduce my self. However, the girl I have been crushin on thinks I like the new girl and now she has started a rumor. I dont know if it has gotten to the new girl but Im worried that since the girl I like has just rubbed thiss off she must not like me the way I like her. I have been thinking about what I can say to the girl I have been crushing on on Facebook chat to let her know that I dont have a crush on the new girl but at the same time let her know that I like her. Im just not sure how to start a conversation asking her how this rumor started and how to let her know its not true. I also have no idea hot to let her know I like her without flat out saying it and making it a big ordeal. Can anyone let me know what I should say to do both of those things?